Counterbalancing mechanism.



A. T. PRESCOTT. GOUNTBRBALANOING MECHANISM.

APPLIUATION FILED 0018, 1909.

Patented Dec. 27, 1910.

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INVENTOR m z/ Z ;Y ATTOENEYS E A. T. PRESCOTT. OOUNTBBBALANGING MECHANISM.

APPLICATION FILED 0OT.B, 1909. 980,126. Batenteu Dec. 27, 1910.

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III/I. IIIIIIIIII 1y -INVENT0R MIM 'ATTORfiEYS 6 -A. T, PRESCOTT. GOUNTERBALANOING MECHANISM. APPLICATION FILED 00T.8, 1909.

Ptented Dec. 27, 1910.

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lNV-ENTOR BY )4I4AIT0ERNEYS Patented Dec.27, 1910.

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INVENTOR WITNESSES:

To all whom it may co'rwem:

UNITED. STATES PATENT OFFI nn'rnun r. rnnsco'rr, .or near cannon; NEW zrnnsnv, .assrenon r enonen n.

FROTHINGHLM 60., A CORPORAIION OF NEW YORK.

OOlI NTEEBALANCING MECHANISM.

Specification of Letters Patent.

Patented Dec. 27, 1910.

- Application filed October 8, 1809. Serial No. 521,785.

Be it known that I, ARTHUR T. Pnusoo'r'r,

a citizen of the United States of America and a resident of East Orange, county of Essex and State of New Jerse have invented certain new and usefu Improvements' in Counterbalancing Mechanism, of

which the followin is a specification, refer- -ence being had to te accompanying drayvings, forming a part thereof.

My invention relates to counterbalancing mechanism, and particularly to means for counterbalancin; a vertically swinging mass of varying weight, proportionately to such weight. ertically swinging do0rs, coal .chutes,.hatchway covers, and the like, are

frequently made in a plurality of sections one of which may be caused to swing vertically by itself, or a plurality ,of which ma be caused to swing vertically together,

an the main object of my present inven tion is to automatically provide for the proper. counterbalancing of the vertically swinging mass whether the mass shall comprise but a single section or a plurality thereof. i

scribed the same as applied to a two-section For the purposes of simplicity and clearness of'description, but without in; tending to-thereby place any limitation or restriction upon my Invention, I have dewarehouse or freight shed door flin which either one or both sections may be swung vertically, at will, one of the said sections being also adapted to be-moved vertically in right lines, and I have shown counterbalancing mechanism comprising a group ing it: wit

therefrom, and an automatic stop for of weights, part of which is arranged to counterbalance the single section when itis arranged to be swung alone, and the'other part of whichv is arranged to be brought into lay to counterbalance the movement of the oor when both sections are caused to be swung together.

My invention also consists in certain novel details of constructionand combine;

' tions of parts including a self locking op-,

erating means for the main, door section,- the j 5 locking feature also acting upon the counterbalancing means so as to support the same even though the means normall connect the door be totally 'sengaged imitin the movement of the vertically movab c section when it is raised independently arrangement is convenient of the other section after the said other section has been swung out of the way.

In order that m invention may be thoroughl understoo I will now proceed to descri e an embodiment thereof in detail, having reference to the accompanying drawings illustrating the same, and will then point out the novel features in claims. 4 In the drawings: Figure 1 is a view in front elevation of a two-section warehouse door with counterbalancing and operatin mechanism connected therewith, constructe in accordance with my invention. Fig. '2'is a view in side elevation thereof, the door sections being shown in vertical transverse section. Fig. 3 is a similar view except that the lower section of thedoor is shown as in its raised position against the ,upper section, the upper section being closed as. in Figs. 1 and 2; partsof the operating mechanism having been removed in order to save space.

asmaller scale, showing the various parts in difi'erent positions. Fig. 6 is a top view showin particularly, the operating and counter alancing mechanism. Fi 7 is a detail top view upon an enlarg scale of certain parts of the operating and counterbalanciiig mechanism at one end of the door. ig. 8 is a detail view showing -a necting the upper door section with its operating mechanism. Fig. 9 is a detailfrag- Figs. 4'and 5 are similar to Fig. 2, but uponmentary view of a modified form of the means for controlling'the counterbalancing "weights, Fig. 10 is a vertical transverse sectional view showing a further modification of the'means for controlling the counterbalancing weights. Fig. 11 is. a detail .view in art front elevation and part longitudina section of certain parts of the ppshown in Fig. 10..

The two-section class of door .is used largely for warehouses and freight sheds,

on docks, and the 'erating mechanism of the, construction '85 slightly modified form' of the means cou-.- T

for a variety of openings. The'upper door; I I

section 10 is pivoted to swing vertically about horizontally disposed pivots 12 ,while the lower door section has arranged to slide vertically in guideways 13. The guideways areso disposed that the lower door section will -'slide, radially with respect to the upper door section 10 over 'the'front face thereof when the said upper sectioi'i is closed (see Figs. 2 and .3), but it is also permitted to slide vertically behind the upper,

door section when the said upper door section is open as appears in Figs. 51 and 5. In this way the lower door section may be raised vertically while the upper door section is closed so as to leave an opening large enough for hand trucks to pass in and out, or the lower door section 'may be raised while the upper door section is closed and then the upper and lower door sections may be swung inward and upward together, so as to leave a much larger opening whereby larger trucks may pass therethrough or freight may be swung in and out therethrough on a rope. Again, in some instances, is it desirable to have an opening for ventilation or light, in which case the lower door section may remain closed and the upper door section only be swung inward and upward, as appears in Fig. 5, or the upper andlower portion of the doorway may be opened while the middle part is closed, by first swinging open the upper door section and then raising the lower door section to the position shown in Fig. 4.

. a minimum of effort.

The counterbalancing mechanism I provide is designed to properly and proportionately balance the movements of the door sections under all of the foregoing condi tions.

The door section 11 is provided with counter-balancing weights 14 connected thereto by chains or other flexible connections 15 which pass over pulleys 16 upona longitudinal shaft 17. Both of the pulleys are preferably secured fast upon the said shaft whereby the uniform rotation of the pulleys compels a uniform lifting stress upon the door section and consequently insures a parallel movementthereof. Stops 18-are provided upon the upper door section- 10 to limit the vertical movement of the lower door section when the same is thus lifted against the front face of the said upper door section. The counterbalancing weights 14: may conveniently be of a. weightsubstantially equal to that of the lower door section, whereby the saidlower door section may be lifted and lowered with The lower door section, as a whole, is of such height as to just overlap the lower edge of the upper door section when both sections are closed, as'in Figs. 1 and 2, but the lower door section 11 is preferably provided wlth a hingedflap 19 at its upper end WlllCll may be swung down when the lower door sectionls' in its lowermost position and it is desired to swing open are shown with the lower door section in its lowermo'- osition, the hinged flap down, and the pper door section swung upward. When the up'pe gjeorsection is thus swung and ments 25 upward the lower door section may still be moved vertically, and to limit the upper movement thereofunder such conditions I have provided apivoted stop 20, such as will engage the upper edge of the lower door section when at the desired limit of its movement under these conditions; the parts are so shown in Fig. 4. This stop is preferably pivoted so as to-pcrmit of its being pushed out of the way by the upper door section when the same is closed (see Figs. 2

From the foregoing itwill be seen that the lower door section may be vertically raised and lowered when the upper door section is either open-or closed,-in the latter case the lower door section will be raised over the face of the upper door section andwill be limited in its movement by the stops 18,

while in the former case it willbe raised behind the upper door section and will be limited by the..pivoted stop or stops 20. In either case the counterbalancing weights 14 will operate to balance .the movements thereo The upper a001- sectionwhich is swung vertically about the pivots 12, as has been mentioned above, may-be soswung after the lower door section has been raised over the face thereof as is shown in Fig.3, or while the lower door section is inits lowermost po sition, as is shownin Fig. 5.; The weight to be lifted will be very much greater; in the former event than in the latter, because, of

course, of the additional weight of the lower door section. In order to counterbalance the movement of the upper door section under either of these conditions I hawre pro; v1ded two counterbalancing weights 7 therefor, one only adapted to be operatively employed when the upperdoor section lifted alone, and the other to be employed in addition when the weight of the lower door section is added thereto. The weights 21 and 22 are connected with the upper door section by means of chains or other flexible connecting means 23 and 24 which are com nected respectively at oneend with the said weights, and atthe other end with cone ele- 26 mounted fast upon a sl1aft 27, and by a chain 28 which is remoxably secured at one end to the said upper door section' at the lower end thereof, and at its other end is secured to and around a cone element 29 also mounted upon the said shaft 27. The chain 23 passes over two direction pulleys 30-31 while the chain 24 may'conveniently pass over a single (llICCtIOII PHllOy 32. The direction pulleyBO may be conveniently in the form of a sprocket wheel so arranged as to havea positive engagement" 55 upper door section the upwar engage 33, the eriphery of which is adapted to be by a brake band 34 The brake band 34 isoperated by aweighted lever 35 the weight of which normally tends to operate door section is in its lowermost position, as

is shown in Figs. 1, 2, and 5, the weight 22 being suflicient at such times to counterbalance the weight of the upper door section 10 alone. .When, however, the lower door section 11is raised upon the face of the door of the upper door section 10 '(as is shown in Fig. 3), the brake mechanism is arranged to be released so as to free the pulley and permit the second weight 21 to come into play. the combined weights being then sufficient to counterbalance the two door sections when moving together.

The release of the brake mechanism is brought about in the following manner: The chains 15 in passing around the pulley 16 upon the shaft 17 cause the said shaft to I tion when the upper. door section is movedrevolve as the lower door section :is raised or lowered as has been stated above; and the said shaft is provided with a drum. 36 around which is coiled a cord 37, the other end of .the cord passing over a direction pulley 38, and being provided at its free end with a button or weight 39. The free end of the cord passes through an eye 40 in the wei hted lever 35, the button or weight 39 being isposed'below the same, and the length of the cord 37 is such that as the lower door section 11 is raised to its up ermost position the winding up of the cor 37 upon the drum 36 will cause the button 39 to engage the underside of the weighted lever 35 and to lift the same so as to free the brake band from engagement with the brake drum 33. Conversely, when the lower door sec-- weighted lever 35 to move downward to agaln operate the brake. Itwill be observed that the pivoted stop 20 at the rear of the upper door section is arranged somewhat lower than are the stops 18, whereby when the lower door section is raised u behind the movement thereof will not be suflicient to release the brake mechanism. or, in other words, sufficient cord 37 will not be wound up upon the drum 36 to cause the button 39 to lift the, weighted lever 35. This, of course, is

essential because the lower door sectionis only lifted up behind the upper door seefreely and independent of the lower door section, and in such case the single weight 22 is the only one which is desired to boil] operation to counterbalance the weight of the-single upper door section 10. g

The cone elements 25'26--29 are provided to compensate for the increase of effective weight of the swinging door sectionor sections as the .same leaves the verti-.

as to cause the weights to be lifted at varying speeds to correctly or approximately correctly counterbalancethe door in all its positions.

The vertically swinging movements above described may be conveniently effected b power imparted to the .shaft 27, and sum power maybe imparted inany desired manner. In the present instance I have shown such means as comprising an endless chain 41 whichis allowed to hang-freely from a pulley 42 secured upon a short cross shaft 43, and a worm and worm wheel gearing 44- connecting the same with the said shaft 27. The advantages of such a construction are, first, thatit is self-locking and will hold the door in any osition to which it is moved, and second, a terthe door has been closed it permits further movements of the o crating mechanism to allow the chain 28 to e readily unhooked or detached from the door so as to permit the lower door section to be raised and lowered over the face of the upper door section, yet at the same time hol mg the counterbalancing weight 21 from running away.

If preferred, and where convenient, two

chains 28'--28" maybe employed in lieu of the single chain 28, which chains may be connected with the lower end of the u per door'section over-the edge of the lower oor section, as is shown in the detail Fig. 8. In such case two similar cone elements 29 29" will, of course, be employed .upon the shaft-27. In this construction it is not necessary to disconnect the chains 28'-28" from the upper door section when the same is closed and the lower door section is raised or lowered.

It will be readily understood that many variations and modifications-of the means for increasing. or decreasing the counterbalancing load employed for the door sections may be employed within the spirit and scopeof my invention, and in Fig. 9 I have shown one such modification in which the second weight 22' may be actually carried upon, and

supported by, the first weight 21 when the active at other times by means of a dog 49 which is carried by a weighted lever 50 cor-- In Figs. and 11 I have shown another modification in which the cord 37 instead of lifting the weighted lever 35, is connected with a clutch operating lever 44 by which the cone element 25 may be secured to, or released from,-opera-tive engagement with the shaft 27. Vhen the lower door section' 11 is raised up and the cord 37 is wound up upon the drum 36, the lever 44 will be pulled over to operate the friction clutch 50 so as to operatively connect the cone element 25 with the shaft -27, while at the (same time a pawl 45 will be lifted out of engagement with the ratchet wheel teeth 46 with which the said cone element 25 is provided, a pin '47 being carried by the lever 44 for such en-. gage'ment with the said pawl.v The two weights will now be in operative engagement with the upper door section to counterbalance the movement thereof and of the lower. section carried with it. hen the lower door section moves downward andthe cord 37 is permitted to unwind, the lever 44 will be moved backward by means of a spring 48 provided for such purpose whereby the clutch will be released and the conical drum or fusee 25 will be disconnected from the shaft 27, the pawl 45 being, however, also released so that it will drop into engagement with the ratchet wheel teeth 46, whereby the weight 21 will be held in its uppermost position and will be prevented from exerting its influence to counterbalance the door'.

\Vhat I claim is: 1. The combination with a horizontally pivoted element and counterbalancing means for applying a counterbalancing load thereto, of an element radially movable-with respect to the said pivoted element, and means operated by the radial movement of the second said element to increase the said counterbalancing load.

2. The combination with a horizontally pivoted element and counterbalancing means for applying a counterbalancing load thereto, of an element, radially movable with respect to the said pivoted element and in one position angularly movable therewith about its pivoted axis, and means operated by the movement of the second said element I to its latter said position to increase the said counterbalancing load.

3. The comb'nation with a horizontally pivoted object comprised in a plurality of sections, and means for lifting -the .same'to move it angularly about its pivotal support, of counterbalancing means therefor,

means for moving one section with relation-"to anotheryother than in the'direction sections, and means for moving the same angularly about its pivotal axis, of counterbalancing means for applying a counterbalancingload thereto, means for movlng one section radially with'relation to the other, and means actuated by the" said radial movement in one direction to lncrease the counterbalancing load.

5; The combination with ahoriz'ontally pivoted element" and aplurality 'of counterbalancing weights therefor,,of an element I radially movable with respect to the said pivoted element, and means operated by the radial movement of the second saidelement (3. The combination with a horizontally I pivoted element, and another element radially movable with respect thereto from a position out ofengagen'ient with the first said "element to a .lposition-to be engaged thereby and angularly moved therewith, of counterbalancingmeans {for vapplying a counterbalancing load to the first said element in its angular movement, and means actuated by the radial movement of the sec-' end said element to vary the said counter: balancing load.

7. The combination with a honizontally pivoted element, and another element radially movable with respect thereto from a position out of engagement with the first said element to a position to be engaged thereby and angularly moved therewith, of

- counterbalancing means for applying a counterbalancing load tothe first said element in .its angular movement, and means actuated by the radial movement of the second said element to its latter said position with respect to the firstsaid element,

to increase the said counterbalancing load.

8. The combination with'a horizontally pivoted element, and another element radially movable with respect thereto from a position out of engagement with the first said element to a position to be engaged thereby and angularly moved therewith, of a pluralityof counterbalancing weights for applying a counterbalancing load to the first said element in its angular movement, and means actuated by the radial movement of the second said element to vary the number of the said counterbalancing weights actively employed.

9. The combination with a two-secti0n element one section of which-is pivotally with the first said section to release the said restraining means.-

10. The combination with a two-section element one section of whichis pivotally suspended and the other of which is movable into and out of lifting engagement with the first said section, a counterbalancingweight forthe first said section, a second counterbalancing weight therefor, a direction pulley, a flexible connection between said second counterbalancing weight and the first said element, and engaging the said direction pulley, means for preventing the rotation of the said pulley, andmeans operated by the movement of the second said section lnto lifting engagement with the first said section, to free the same and thus permit the free rotation of the said pulley.-

11. The combination with a two-section element one section of which is pivotally, suspended and the other of which is movable into and out of lifting engagement with the first said section, a'counterbalane ing weight for the first said section, a sec-. ond counterbalancing weight therefor, adi-' rection pulley, a flexible connection between said second counterbalancin'g weight and the first said element, and engaging the said direction (pulley, a brake drum connected with said irection pulley, a brake in engage, ment therewith, and means operated by the movement of the second said section into lifting engagement with the first said section, v to release the said'brake.

12. The combination with a two-section door one section of which isadapted to be moved into and out of lifting engagement with the other section, of counterbalancing means for the latter section, and means controlled by the moving of the former section into lifting en agement with the latter to a increase the sai counterbalancing load.

13. The combination with a two-section door one section of which is pivotally suspended and the other section of which is adapted to be moved into and out of lifting engagement with the first said section, of independent counterbalancing means for the two said sections, and means controlled by the moving of the latter section into lifting engagement with the former, to increase at such times the counterbalancing load upon the first said section.

14. The combination with a two-section door one section of'which is pivotally-suspended and the other section of which is adapted to be moved into and, out of lifting engagement with the first said section, of means for counterbalancing the latter section when it is so moved, means for counterbalancin the former section when the same is move about its pivotaLsu port, and means controlled by the moving of said section into lifting engagement with the first said section, to increase at such times the counterbalancing load upon the section, a counterbalancing weight for the first said section, another counterbalancing weight for the first ,said section, and means operated by the moving of the second saidsection into lifting engagement with the first said section to operatively engage the last said counterbalancing weight with the first said door section, and operated b the moving of the second said sectionoutro liftthe second ing engagement with the first said section to operatively disconnect the last said weight from the first said door section.-

16. The combination "with a two-section door one section of which is pivotally suspended and the other section of WhlCh is vertically movable in right lines,-of independent counterbalancing means for the two said door sections, and means operated by the vertical movement of the second said door section to increase the counterbalancing load upon the said pivotally suspended door section. r

17. The combination with a-two-section door one'section of which is pivotally suspended and the other section of which is arranged to move vertically in ri ht lines, of a counterbalancing weight for t e said vertically movable section, an element rotated by the relative movement of the said section and counterbalancing weight, counterbalancing means for the said swinging door section, and means controlled b the said rotatable element for varying t e counterbalancing load for the said swinging door section.

element one section of which is ivotally suspended and the other of whic is movable nto and out of lifting engagement with the first said section, a counterbalancing weight for the first said section, a second'counter .balancin weight therefor, acounterbalancing we'ig t for the second said section in its I door one section of which is pivotally sus- 18. The combination with a two-section pended and the other Fsetition of which is arranged to move radially with respect thereto into and out of liftingengagement there- -With, of connterbalanci'ng means for the first 20. The combination with a two-section doorone seetion of which is pivotally suspended, ahdtheother section of which is vertically movable in right lines to a position upon the face of the first said section when the first said section is closed, or to a position behind and clear of the first said section when the first said section is swung open, of a stop for limiting the right line movement of the second said door section under the first mentioned conditions, and a second stop for limiting the said right line movement of the second said door section under the second said conditions to prevent its moving as far as under the said first mentioned conditions;- i

21. The combination with atwo-section door, one section of which is pivotalli suspended and the other section of which is vertically movable in right lines, of a stop terbalancin means for the door, means operated by 516 movement of the second said section for varying the connterbalancing load of the connterbalancing means, a stop for limiting the right line movement of the second said section when the first said section is in one position, and another stop for limiting the right line movement of the second said section to a different degree, when,

the first said section is in another position.

23. The combination with a two-section door, one section of which is pivotally sus pended and the other section of which is vertically movable in right lines, of a stop upon the first section for limiting the right line movement of the second section .when the first said section is in one position, and a stop carried by a portion independent of the door for limiting the right line movement of the second said section to a ditferent degree when the first said section is in another position.

In witness whereof I have hereunto set myhand this 3rd day of October, 1909. ARTHUR T. PRESCOTT. \Vitnesses: a

D. ENID DnU'rscrr, l lona'rro OKEEFE. 

